Nginx工作进程退出

我从/var/log/nginx/error.log收到以下错误消息：

2014/07/17 08:36:21 [alert] 8206#0: worker process 8207 exited on signal 11 (core dumped)
2014/07/17 08:36:21 [alert] 8206#0: worker process 8210 exited on signal 11 (core dumped)
2014/07/17 08:36:22 [alert] 8206#0: worker process 8208 exited on signal 11 (core dumped)
2014/07/17 08:36:26 [alert] 8206#0: worker process 8209 exited on signal 11 (core dumped)
2014/07/17 08:36:26 [alert] 8206#0: worker process 8232 exited on signal 11 (core dumped)
2014/07/17 08:36:26 [alert] 8206#0: worker process 8236 exited on signal 11 (core dumped)

/var/log/nginx/access.log显示重定向到https,如果您访问http地址,则会发生这种情况：

[17/Jul/2014:09:22:54 +0000] "GET / HTTP/1.1" 301 185 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_5) AppleWebKit/537.76.4 (KHTML,like Gecko) Version/6.1.4 Safari/537.76.4"

可能导致这种情况的任何想法？它位于Ubuntu 12.04和标准的apt-get install nginx上.

这是配置：

server {
    listen      80;
    server_name domain.com;
    rewrite     ^ https://$server_name$request_uri? permanent;
}

server {
    listen                  443 ssl;
    server_name             domain.com;
    ssl_certificate         /ssl/path.crt;
    ssl_certificate_key     /ssl/path.key;
    error_page              404             /404.html;
    error_page              500 502 503 504 /50x.html;
    location                = 50x.html {
        root    /usr/share/nginx/html;
    }
    location                / {
        root    /project/path/root;
    }
    access_log              /project/path/logs/nginx-access.log;
    error_log               /project/path/logs/nginx-error.log;
    client_max_body_size    20m;
}

当我使用Safari查看网站时,我只会收到此错误,它发生在多台计算机上,而不仅仅是我的,并且每个Safari上显示的错误相同.